Braiterman links to an extraordinary article by Marcy Brink-Danan which goes into more detail.* The founding figures of modern anthropology included a strong Jewish contingent, but paradoxically this did not lead to sustained interest in studying Jewish culture for two main reasons. First, because the primary late-19th/20th century strategy for combating anti-Semitism was to stress Jewish similarity and assimilation into mainstream culture, Jews seemed to offer little to study that differed from the majority. Second, continued currents of anti-Semitism dissuaded many Jewish academics from pursuing identifiably "Jewish" topics, for fear of being typecast, pigeon-holed, or worse. The result is that Jewishness occupied an intellectual "no-mans land", where it was not accepted as a true outgroup (either by insiders devoted to that project or, later, minority scholars seeking to change the conversation from below) while also not being incorporated inside the dominant narratives.
This basic narrative is one I have observed in quite a few other disciplines (Evelyn Beck compellingly documented it in women's studies, for example). Jews occupy a space that is, if not entirely unique, then certainly unfamiliar in the public imaginary. They are at the margins of the margins; the outgroup that's in. Thought of as too mainstream to be studied as an outgroup, Jews are likewise too differentiated to have their experiences adequately captured by the ubiquitous majoritarian discourses that more critical commentators claim to be interested in undermining. This is buttressed by the more classic anti-Semitic trope of Jewish hyperpower: it's hard to conceptualize Jews as a "real" outgroup because the idea that Jews are super-privileged, world-dominating figures is deeply woven into the public conceptualization of Jewishness. The old anti-Semitism and the new work in perfect harmony. And so anthropologists (and others) don't see the need to encounter Jewish specificity because they assume that Jews are anti-discrimination winners -- they've already "made it" and the discipline can accordingly move on to look at the "real" victims (of which Jews by definition are not). Jewish voices are assumed to have been already heard -- if not overheard -- even in spaces when they actually have been largely silenced.
One upshot of this outlook is that Jews occupy a peculiarly vulnerable space on the left (the also are vulnerable from the right for other reasons). The left project is intensely concerned with normative change, but is deeply skeptical of its ability to do so in a non-oppressive, non-imperial way across cultures. The natural inclination, then, is to engage in self-critique -- but of course, such criticism runs the risk of undermining very real privileges that progressives in the west enjoy and take for granted. Enter the Jews. They are the outgroup you're allowed to target because they're not "really" an outgroup; even though the tactics employed against them only work because of their marginal status. Jews are marginal like other outgroups (though not necessarily in the same way as other outgroups), can be dominated like other outgroups, but they lack the standing to assert claims as an outgroup (demanding, for example, degrees of deference or heightened protection or acknowledgment of difference) that the left is, in other contexts, willing to recognize. It's a move of projection -- Israel is the bad us.
The boycott campaign, for example, depends precisely on a massive asymmtery of power even as it self-constructs as resistance to power (Jewish power -- Jews are inherently powerful, after all -- but also "our power", since the Jews are simply a transplanted and slightly quirky iteration of "us"). It leverages anti-Semitic domination even in the course of denying it (in the process of denying Jewish specificity altogether). A counter-boycott by Israeli academic groups of American anthropologists, for example, would have less than no impact -- materially, it's limited by the raw fact that there just aren't that many Israelis, and symbolically it lacks any real punch because hearing less from those overbearing, superprivileged Jews is a feature rather than a bug. This is why a boycott of Israel "works" in a way that a boycott of, say, Chinese universities wouldn't; in addition to simply being in a better position to fight back, if Chinese voices expressed a sense of alienation or disregard then American academics would experience that as a meaningful loss in a way that they don't when it comes to the Jews. What "loss" is there, when Jews already (we're told) have their stories woven into the dominant narratives we hear every day?
All of this reminds me of how one British writer reasoned through his particular emphasis on Israeli human rights violations as compared to those of other nations; since it (obviously) wasn't anti-Semitism (it never is), he settled on the sense that Israel was basically "an English county planted on the Mediterranean shores." Having erased Jewish differentiation entirely, targeting Israel becomes not the delicate project of assailing an embattled other, but the noble and virtuous project of self-critique. As I put it: "It's all the joy of liberal guilt-induced self-flagellation, except the wounds show up on someone else's body."
* "Anthropological Perspectives on Judaism: A Comparative Review," Religion Compass 2/4 (2008): 674–688,